Femtocell experts create even tinier porta-base station

Femtocell experts Ubiquisys have designed an even smaller network base station that you can take on holiday to dispense with roaming rates forever - if your network will let you.

The Attocell, as Ubiquisys would have it, broadcasts at such low power that it's legal to use in many countries, including America, without a licence. That might limit the range to as little as a few millimetres, but combined with a Bluetooth headset it could enable the user to make mobile calls to and from the home network when a long way from home.

Femtocells are tiny base stations that connect back to the macro network over the internet, but broadcast standard cellular signals to normal handsets, so providing network coverage where there is none. Vodafone brands them Sure Signal in the UK, while Sprint and AT&T sell them to Americans who lack coverage, but you can't take them with you when you're travelling.

That's because Vodafone, and thus its Sure Signal boxes, uses spectrum starting at 2.1349GHz to communicate with the phone (3G uplink), but the operator only has a licence to do so in the UK - take your SureSignal box to France and you'll broadcasting illegally and Vodafone's back end will refuse the connection from a French IP address*. In America the situation is complicated by the regional nature of radio licences, which require every femtocell to be fitted with GPS to ensure it's not stepping on anyone's toes.

But Ubiquisys' Attocell can ratchet its transmission power down below the licence floor, which makes it legal to use in some countries (including the USA, though not the UK). That limits the range, perhaps to a meter or two, or even a centimetre, but that might be a limitation worth getting used to in order to avoid paying any roaming fees.

Not that the Attocell is anything more than a handful of prototypes today, designed to plug into a laptop's USB port and not yet endorsed by any network operator. Ubiquisys tells us that operators are interested, and not worried about potential abuse by globetrotting executives who didn't read the list of countries in the small print - which is unsurprising when it's the user, not the operator, who would be breaking the law.

Operators, it seems, are more concerned about the loss of revenue their roaming partners would experience if customers started using attocells: a problem that technology can't solve. ®

* You could conceal your address behind a UK-based VPN, but that wouldn't make it legal.